Olympus E-420 Review

ISO / Sensitivity accuracy

In this section of our reviews we are measuring the actual sensitivity of each indicated ISO sensitivity. This is achieved using the same shots as are used to measure ISO noise levels, we simply compare the exposure for each shot to the metered light level (using Sekonic L-358), middle gray matched. We estimate the accuracy of these results to be +/- 1/6 EV.

Like its predecessor the E-420 proved to have inconsistently indicated ISO sensitivities. In reality ISO 100 proved to be marginally more sensitive than indicated (more like ISO 125).

Indicated
sensitivity

Olympus E-420 (actual sensitivity)

Canon EOS 450D(actual sensitivity)

Nikon D60 (actual sensitivity)

ISO 100

ISO 125

ISO 100

ISO 100

ISO 200

ISO 200

ISO 200

ISO 200

ISO 400

ISO 400

ISO 400

ISO 400

ISO 800

ISO 800

ISO 800

ISO 800

ISO 1600

ISO 1600

ISO 1600

ISO 1600

ISO 3200

n/a

n/a

ISO 3200

ISO Sensitivity / Noise levels

ISO equivalence on a digital camera is the ability to increase
the sensitivity of the sensor. The works by
turning up the "volume" (gain) on the sensor's signal amplifiers (remember the sensor is an analogue device). By amplifying the signal you also amplify the noise which becomes more visible at higher ISO's. Many modern cameras also employ noise reduction and / or sharpness reduction at higher sensitivities.

To measure noise levels we take a sequence of images of a GretagMacBeth ColorChecker chart (controlled artificial daylight lighting). The exposure is matched to the ISO (ie. ISO 200, 1/200 sec for consistency of exposure between cameras). The image sequence is run through our own proprietary noise measurement tool (version 1.4 in this review). Click here for more information. (Note that noise values indicated on
the graphs here can not be compared to those in other reviews). Room temperature is approximately 22°C (~72°F), simulated daylight lighting.

As you would almost expect there is little difference in terms of noise between the digital SLRs in this comparison up to ISO 400. At ISO 800 and 1600 the Olympus clearly applies more luminance noise reduction than the Canon and Nikon, resulting in a 'cleaner' but less detailed image. The Canon 450D (Rebel XSi) provides the most balanced output, managing noise well and preserving a lot of detail up until the high ISO regions.

Gray luminance noise graph

The E-420's noise curve is almost identical to its predecessor's. It keeps measurable noise virtually flat from ISO 100 (125) to 800, rising only slightly at ISO 1600 (1250).

Indicated ISO sensitivity is on the horizontal axis of this graph, standard
deviation of luminosity on the vertical axis.

Black luminance noise graph

Indicated ISO sensitivity is on the horizontal axis of this graph, standard
deviation of luminosity on the vertical axis.

Chroma (color) noise graph

Chroma noise reduction works pretty much the same way system as the luminance variant, the curve is being kept very flat throughout the entire sensitivity range.

Indicated ISO sensitivity is on the horizontal axis of this graph, standard
deviation of color on the vertical axis.

Comments

I have had this DSLR for almost a year, as it is my first one. It came with two lenses, and one of the lenses recently has been having problems focusing. I had bought it refurbished, so that could have been the problem. Other than that, I have loved it. It takes great pictures, and is nice and compact. I don't know how it works in its automatic settings, as I only use any camera in full manual mode. But for a first DSLR, I have loved it, and I would use an olympus any day.

I bought this oldie digital as a first experience vith digital cameras, even still use film mainly. So may it was a wrong decision, but I stay beside classic film photography. This camera slow, cheap and only manual mode able to firing promptly. I missed such a moments just because it wait so much before release the shutter. The lens as it is, so far from my zeiss with contax 35mm. Obviously nonsense to compare 66 rolleiflex images. There are lots of set up features, but practically takes long time to modify them, which disturb so much the picture taking. The CF card door a slim plastic door, very fragile. The viewfinder very small. All around this model are far away any real reflex cameras, it seems who design it just never take pictures with a proper camera. I can not recommend this camera, better to smash them all in the name of photography.